HBASE-24517 AssignmentManager.start should add meta region to ServerStateNode (#1866)

Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: Wellington Ramos Chevreuil <wchevreuil@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java

@@ -231,17 +231,15 @@ public class AssignmentManager {
       RegionState regionState = MetaTableLocator.getMetaRegionState(zkw);
       RegionStateNode regionNode =
         regionStates.getOrCreateRegionStateNode(RegionInfoBuilder.FIRST_META_REGIONINFO);
-      regionNode.lock();
-      try {
-        regionNode.setRegionLocation(regionState.getServerName());
-        regionNode.setState(regionState.getState());
-        if (regionNode.getProcedure() != null) {
-          regionNode.getProcedure().stateLoaded(this, regionNode);
-        }
-        setMetaAssigned(regionState.getRegion(), regionState.getState() == State.OPEN);
-      } finally {
-        regionNode.unlock();
+      regionNode.setRegionLocation(regionState.getServerName());
+      regionNode.setState(regionState.getState());
+      if (regionNode.getProcedure() != null) {
+        regionNode.getProcedure().stateLoaded(this, regionNode);
       }
+      if (regionState.getServerName() != null) {
+        regionStates.addRegionToServer(regionNode);
+      }
+      setMetaAssigned(regionState.getRegion(), regionState.getState() == State.OPEN);
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestAssignmentManagerLoadMetaRegionState.java

@@ -0,0 +1,76 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.assignment;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.client.RegionInfo;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({ MasterTests.class, MediumTests.class })
+public class TestAssignmentManagerLoadMetaRegionState {
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+    HBaseClassTestRule.forClass(TestAssignmentManagerLoadMetaRegionState.class);
+
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  @BeforeClass
+  public static void setUp() throws Exception {
+    UTIL.startMiniCluster(1);
+  }
+
+  @AfterClass
+  public static void tearDown() throws IOException {
+    UTIL.shutdownMiniCluster();
+  }
+
+  @Test
+  public void testRestart() throws InterruptedException, IOException {
+    ServerName sn = UTIL.getMiniHBaseCluster().getRegionServer(0).getServerName();
+    AssignmentManager am = UTIL.getMiniHBaseCluster().getMaster().getAssignmentManager();
+    Set<RegionInfo> regions = new HashSet<>(am.getRegionsOnServer(sn));
+
+    UTIL.getMiniHBaseCluster().stopMaster(0).join();
+    HMaster newMaster = UTIL.getMiniHBaseCluster().startMaster().getMaster();
+    UTIL.waitFor(30000, () -> newMaster.isInitialized());
+
+    am = UTIL.getMiniHBaseCluster().getMaster().getAssignmentManager();
+    List<RegionInfo> newRegions = am.getRegionsOnServer(sn);
+    assertEquals(regions.size(), newRegions.size());
+    for (RegionInfo region : newRegions) {
+      assertTrue(regions.contains(region));
+    }
+  }
+}